Page 13: Metaphase II


Metaphase II in Mayapple. In meiosis II, the chromatids within each chromosome continue to show the appearance of repelling each other as they did in anaphase I. This makes the appearance of metaphase II different from that of a mitotic division. Many textbooks describe meiosis II as being essentially like mitosis. Here are the differences between meiosis II and mitosis. (1) There was no DNA synthesis and chromatin replication in the interphase prior to meiosis II, whereas DNA synthesis and chromatin replication always precede mitosis. (2) Because of crossing over, the chromatids in a chromosome in meiosis II are not genetically identical, but the two chromatids in a mitotic chromosome are genetically identical. (3) The chromatids in a meiotic II chromosome appear to repel each other, whereas in a mitotic chromosome the chromatids are tightly wound around each other as in the image of onion mitosis in the next page.